A High-Performance MoS 2 -Based Visible–Near-Infrared Photodetector from Gateless Photogating Effect Induced by Nickel Nanoparticles

Recent advancements in two-dimensional materials have shown huge potential for optoelectronic applications. It is challenging to achieve highly effective and sensitive broadband photodetection based on MoS 2 devices. Defect engineering, such as introducing vacancies, can narrow the bandgap and boost the separation of photogenerated carriers by defect states but leads to a slow response speed. Herein, we propose a nickel nanoparticle-induced gateless photogating effect with a unique energy band structure to enable the application of defect engineering and achieve high optoelectronic performance. The device based on Ni nanoparticle-decorated MoS 2 with S vacancies exhibited high responsivities of 106.21 and 1.38 A W −1 and detectivities of 1.9 × 10 12 and 8.9 × 10 9 Jones under 532 and 980 nm illumination (visible to near infrared), respectively, with highly accelerated response speed. This strategy provides new insight into optimizing defect engineering to design high-performance optoelectronic devices capable of broadband photodetection.